mouse monoclonal IgG1; ErbB3/HER3 Antibody (RTJ.2) is an IgG1 κ mouse monoclonal ErbB-3 antibody (also designated ErbB-3 antibody) that detects ErbB-3 of mouse, rat and human origin by WB, IP, IF, IHC(P) and FCM. ErbB3/HER3 Antibody (RTJ.2) is available as the non-conjugated anti-ErbB-3 antibody form, as well as multiple conjugated forms of anti-ErbB-3 antibody, including agarose, HRP, PE, FITC and multiple Alexa Fluor® conjugates. The EGF receptor family comprises several related receptor tyrosine kinases that are frequently overexpressed in a variety of carcinomas. Members of this receptor family include EGFR (HER1), Neu (ErbB-2, HER2), ErbB-3 (HER3) and ErbB-4 (HER4), which form either homodimers or heterodimers upon ligand binding. Full length ErbB-3 is overexpressed in human mammary tumors. The ErbB-3 gene also produces several alternative variants, including a secreted form of which negatively regulates heregulin stimulated ErbB activation. ErbB-3 heterodimerizes with Neu and binds heregulin in order to activate phosphoinositide (PI) 3-kinase. The recruitment and activation of PI 3-kinase occurs via its interaction with phosphorylated YXXM motifs in the carboxy terminus of ErbB-3.